Fisherman Aart van der Waal pulls in his nets in the polders surrounding the Southern Dutch Village of Numansdorp September 28, 2009.

Credit: Reuters/Jerry Lampen

OSLO (Reuters) - The U.N. panel of climate experts overstated how much of the Netherlands is below sea level, according to a preliminary report on Saturday, admitting yet another flaw after a row last month over Himalayan glacier melt.

A background note by the Intergovernmental Panel on Climate Change (IPCC) said a 2007 report wrongly stated that 55 percent of the country was below sea level since the figure included areas above sea level, prone to flooding along rivers.

The United Nations has said errors in the 2007 report of about 3,000 pages do not affect the core conclusions that human activities, led by burning fossil fuels, are warming the globe.

"The sea level statistic was used for background information only, and the updated information remains consistent with the overall conclusions," the IPCC note dated February 12 said.

Sceptics say errors have exposed sloppiness and over-reliance on "grey literature" outside leading scientific journals. The panel's reports are a main guide for governments seeking to work out costly policies to combat global warming.

The 2007 report included the sentence: "The Netherlands is an example of a country highly susceptible to both sea level rise and river flooding because 55 percent of its territory is below sea level."

"A preliminary analysis suggests that the sentence discussed should end with: 'because 55 percent of the Netherlands is at risk of flooding'," the IPCC note said.

The Netherlands Environmental Assessment Agency, the original source of the incorrect data, said on February 5 that just 26 percent of the country is below sea level and 29 percent susceptible to river flooding.

The IPCC said the error was widespread -- it quoted a report from the Dutch Ministry of Transport saying "about 60 percent" of the country is below sea level, and a European Commission study saying "about half."

The panel expressed regret last month after admitting that the 2007 report exaggerated the pace of melt of the Himalayan glaciers, which feed rivers from China to India in dry seasons, in a sentence that said they could all vanish by 2035.